sumazab

Hi There, This is my first post, and it is regarding Cisco VLan configuration. I configured a router on a stick. Created 2 subinterface. One with 10.0.0.1/24 and 192.168.2.1/24. I created 2 Vlans, and i put 2 computers in each VLANS. How do i configure so that both VLAN's dont communicate with each other? the computers on vlan 10, i dont want them to communicate with the computers on vlan 20. I hope this is the right location for my post. THanks in advance,